A Breakthrough in Non-Invasive Cancer Treatment

Researchers from Eindhoven University of Technology have announced a significant leap forward in a non-invasive method for cancer treatment

Prof. Jan C.M. van Hest and his team at Institute for Complex Molecular Systems partnered with several Chinese research institutions to test a nanotechnology that addresses the drawbacks to photodynamic therapy, an emerging cancer treatment.

What is Photodynamic Therapy?
Photodynamic therapy (PDT), is a form of phototherapy involving light and a photosensitizing chemical substance, used in conjunction with molecular oxygen to elicit cell death.
Basically when the chemical reaches tumour, it is activated with a laser which creates singlet oxygen eventually leading to cell death.
It is a non-toxic, non-surgical cancer treatment that’s on the rise in several countries.
In February 2019, medical scientists announced that iridium attached to albumin, creating a photosensitized molecule, can penetrate cancer cells and, after being irradiated with light, destroy the cancer cells.

A paper outlining the research recently appeared in the journal ACS Nano.

Though PDT sounds great, it has its problems, mainly there are three problems which are
1. The photosensitizing chemical needs to be directed to accumulate around the tumor.
2. The reaction needs oxygen molecules in order to create singlet oxygen, and tumors create low-oxygen environments.
3. Tumors have a defensive substance that breaks down singlet oxygen.

The current research seems to solve all the three problems at once.

The research team designed a single nanoparticle that could solve all three problems. It’s coated with polymers that are triggered by the tumor’s acidic environment to attach themselves to the tumor. The polymers are held together by the photosensitizer, acting as both container and key cargo.

A catalase carried by the particle breaks down hydrogen peroxide from the tumor to produce an abundance of oxygen. Meanwhile, another compound in the particle breaks down the defensive substance and, as a nice side effect, releases manganese that facilitates MRI imaging.

“It’s an elegant solution in which each piece works together to disable the defense mechanisms of the tumor,” says Professor van Hest. The components are either destroyed in their intended reaction or easily flushed from the system. Best of all, the particles would be relatively easy to mass-produce.

The researchers will be further testing it and they hope that they will make significant advances in the PDT method of treating cancer.

Journal Reference:
Jianzhi Zhu et al. Surface-Charge-Switchable Nanoclusters for Magnetic Resonance Imaging-Guided and Glutathione Depletion-Enhanced Photodynamic Therapy, ACS Nano (2020). DOI: 10.1021/acsnano.0c03080